1. Field of the Invention
The present invention relates to an intraperitoneal therapy apparatus for performing pneumoperitoneum, inflating the peritoneal cavity of a patient, and for cauterizing diseased tissues within the inflated peritoneal cavity.
2. Description of the Related Art
Intraperitoneal therapy has been practiced widely, with the aid of endoscope. Recently, gallbladder extraction is often performed, while viewing the interior of the peritoneal cavity through an endoscope.
To achieve such a medical treatment, the peritoneal cavity is inflated so that a wide view field and a large space may be acquired for easy endoscopic operation. More precisely, CO.sub.2 gas is supplied into the peritoneal cavity by means of a pneumoperitoneal device, thereby inflating the peritoneal cavity.
Diseased tissues in the peritoneal cavity, thus inflated, are cauterized by using a cautery device such as a high-frequency cautery device or a laser device, while observing the tissues through an endoscope. The tissues being cauterized emit fume. The fume may fill the peritoneal cavity will be so density that the interior of the cavity cannot be seen through the observation window of the endoscope.
In the event of fume-emission in the abdominal cavity, the cautery device is stopped. Then, the endoscope and other medical instruments are pulled out of the peritoneal cavity through the trocars piercing into the cavity. Next, the pneumoperitoneal device is driven, introducing CO.sub.2 gas into the peritoneal cavity and naturally expelling the fume from the cavity via the trocars.
The fume may be removed from the peritoneal cavity by an alternatively method. For example, as is disclosed in German Patent Specification DE 37 06 717, the CO.sub.2 gas and the fume are strongly pumped out of the peritoneal cavity, then they are passed through a disinfection filter, thus filtering out the fume, and the CO.sub.2 is introduced back into the peritoneal cavity.
These fume-expelling methods are disadvantageous, however.
In the first method, it takes a relatively long time to expel the fume completely from the cavity. Inevitably the cautery device must be left unused for that long time, lengthening the time needed to complete the cautery, and the patient must suffer pain for a Long time. Further, the CO.sub.2 is removed from the peritoneal cavity, along with the fume, reducing the intraperitoneal pressure and deflating the cavity. Consequently, pneumoperitoneum must be performed again to inflate the cavity to the initial state so that the therapy can continued.
In the second method, the flow rate at which the cleaned CO.sub.2 gas is supplied back into the peritoneal cavity decreases due to the resistance the disinfection filter exhibits to the flow of the CO.sub.2 gas. As a con sequence, the intraperitoneal pressure will fall, and the cavity will be deflated. To inflate the cavity to the initial degree, it takes a long period of time.